Concerned with software or hardware firewalls

learn more… | top users | synonyms (1)

3
votes
1answer
146 views

Are Keystroke and Click Loggers Legal? [closed]

I worked with the firewall "Nobero" which is paid and bit expensive. It is a complete Network Firewall including groups policy, banning URLs and social sites. But It has a feature of tracking users' ...
3
votes
1answer
119 views

IPsec: Is AH in tunnel mode secure?

I have a site-to-site IPsec VPN which was performing poorly (10 -20% upload/download speeds as a percentage of available WAN circuit bandwidth) when using ESP in tunnel mode with DES encryption and ...
3
votes
1answer
149 views

Tracking down the source of email attacks

For the past week our company's IDS has been blocking 100-200 meeting invite emails per day from a specific client that are loaded with buffer overflows targeted at Exchange 2003. The payloads are ...
3
votes
1answer
747 views

Limit BitTorrent Sync connections to a specific network

Is it possible to limit BitTorrent Sync connections to a a specific network using the client software? Right now the closest I can come up with would be IP limitations imposed on each client using a ...
3
votes
3answers
9k views

Config Server Firewall: What Outgoing ports need to be open for wget and apt-get install?

I am just configuring CSF and I have to specify my outbound ports here. I am trying to close as many as possible leaving only what I need open, however what do I need to leave open for wget? # Allow ...
3
votes
1answer
2k views

How can I find the process that is trying to use smtp to send email?

Previously I asked Who (which process) is calling curl? and I got very good answers (this answer in particular) which basically replace the curl binary with a shell script that logs each call to curl ...
3
votes
1answer
5k views

Is opening both TCP/UDP less secured than just TCP or UDP when needed and why?

If application needs opened port X UDP, or X TCP combination. Is there any potential risk by opening both UDP/TCP as I usually am not sure which one the application uses?
3
votes
2answers
131 views

Firewall UDP Packet Source Port 53 Ruleset Bypass

I have a question regarding recent PCI DSS scan performed on our network. On some of the Windows 2008 servers (physical and VM), there is a risk found "Firewall UDP Packet Source Port 53 Ruleset ...
3
votes
1answer
498 views

Is it possible to force client use TCP instead UDP for DNS queries?

Assume I am managing a firewall between DNS server and clients. Is there any way to force clients use TCP rather than UDP, so we can prevent DNS spoof types of DDoS attacks?
3
votes
1answer
171 views

Security of OpenVPN against sophisticated DPI solution

I'm planing to build a device (prototype) that act as a portable security gateway. To make this, I choosed OpenWRT running on Raspberry Pi with OpenVPN for VPN connection. My main purpose of this ...
3
votes
3answers
197 views

Segregating a Printer in my Enterprise Network

I have a EAP-TLS network at home which I've managed for some time now. I just got a new Brother HL-5470 printer so I can finally print things at home, which is really nice. The only problem is that ...
3
votes
4answers
115 views

Do I need antivirus for this unusual installation - or just firewall?

I'm donating an old Windows XP laptop to a school. The machine will spend its golden years doing only one thing - a process that consists of just three steps: Recording lectures and discussions ...
3
votes
1answer
2k views

Expose web service in a secure manner

Requirement I have a web service I need to expose on the DMZ for external communication. The web service communicates directly with a critical database that sits on an internal net. Current ...
3
votes
5answers
188 views

Windows: Any method to enforce user confirmation before the browser opens a URL requested by an external desktop app?

A robust outgoing firewall will protect against desktop applications directly connecting to the internet without your permission. However, as the browser is a generally authorized application for ...
3
votes
1answer
999 views

Isolate a Virtualbox VM from local network [closed]

I have the need to isolate a virtual machine created with Virtualbox from the local network but I need to provide internet access to that machine. It is the first time that I face this kind of ...
3
votes
1answer
121 views

SYN scan, determining scan vs large file upload

In a system attempting to detect SYN scans, one technique is to analyze the rate of change of (network packets sent from victim host per second). Processes such as uploading a large file would not be ...
3
votes
1answer
531 views

SSL VPN placement strategies

I wanted to know the advantages and disadvantages of placing an SSL VPN with respect to CIA in different locations: with firewall within the internal network within the DMZ Any reference also ...
3
votes
1answer
281 views

Why strip accept-encoding?

It seems that there are multiple "security" products which strip or mangle 'Accept-encoding' headers, thus forcing non-compressed responses from HTTP servers. I've been trying to imagine if there's ...
3
votes
2answers
606 views

1 PIX firewall, 2 routers, 2 switches. Please answer a couple questions about hack lab

I bought a bunch of cisco equipment for a project and I got 1 PIX firewall 2 switches and 2 routers This is my plan for a topology but I am new at this so I need help. I am basing this off the ...
3
votes
1answer
39 views

Better alternative to WAF path whitelisting?

We are managing a WAF which is being used by some applications. Recently I tried to use a Valid URL module to white list all the APIs and static resources of an application. Although from the security ...
3
votes
2answers
86 views

How to restrict access to the internet for some computers on the network?

I’d like to differentiate machines (or, possibly, users) on my small business network so that only some of them have access to the internet. The solution I’ve been using to this day is quite terrible: ...
3
votes
2answers
298 views

how can an attacker access a system through a compromised router?

Let's say an attacker gained access to the admin panel of a home router with port 21, 23 and 80 open. I mean the attacker has full control over the router, thus being able to port forward, etc... ...
3
votes
2answers
127 views

When should I drop a packet with ICMP type 3, code 9 or 10, TCP RST, or TCP ACK?

This answer says there are a few ways of dealing with a blocked packet at a firewall: At each of these levels a 1st IP packet (and any other protocol packet as an ESP or AH packet) might receive ...
3
votes
1answer
132 views

Can NATs and firewalls blacklist IPs when trying to UDP hole punch?

I am developing a P2P application that will make use of UDP hole punch to connect two peers behind NAT. When dealing with connections between a cone and a symmetric, unpredictable NATs, however, hole ...
3
votes
2answers
4k views

Blocking incoming traffic from privileged port (< 1024) to mitigate DNS DDos Amplification attacks

Hope someone can clarify. As I understand, in a DNS DDos Amplification attacks Multiple DNS queries are sent to a vulnerable name server with the source IP spoofed to that of the target server. The ...
3
votes
5answers
428 views

Enforcing personal firewall for OS X

We're currently doing PCI compliance, and one of the requirements is that mobile devices that have access to systems involved in processing card data have personal firewall software installed which ...
3
votes
1answer
1k views

HTTPS form submissions are blocked on corporate networks

We have an HTML form which is submitted via HTTPS. We've noticed that when the form is submitted on a home network, it seems to go through just fine. However, when the form is submitted on certain ...
3
votes
1answer
2k views

w00tw00t.at.ISC.SANS.DFind iptables fix - abusable?

It's only an idea. I've recently logged that my server is scanned by w00tw00t tools. I found many solutions to this, such as use of apache mod-security, fail2ban, etc.. The one I want to speak ...
3
votes
1answer
899 views

Mac sending hundreds of packets to gateway

I've got a user on my work network who brings her personal laptop (macbook) in for work. They've been having some horrendously slow network issues on everything past that hub, so I did some packet ...
3
votes
0answers
52 views

Modifying shell code to bypass Windows Firewall

As part of my OSCP's training, I'm supposed to get a shell on a Win7 machine using browser's exploit (MS12-037) with Windows firewall on. I have an idea but I'm having hard time applying it. What ...
3
votes
0answers
74 views

I'm looking for a decent book on network and infrastructure security [closed]

I'm currently looking for a decent book on network and infrastructure security (especially in the enterprise context). Could you point me to one or two recent books, please? Thanks a lot in advance! ...
3
votes
0answers
1k views

cisco asa syn flood detection and response not working

I have a Cisco ASA 5510 (ASA Version 8.3(2)) that has been getting a syn flood attack on it (or more accurately through it - targeting a host behind it) a couple of times a day for the past few days. ...
3
votes
2answers
213 views

How common is port-knocking? [closed]

Today I read about port-knocking for the first time. It has been a pretty known concept for more than ten years, but I don't know anybody who uses it for their servers. How common is the usage of ...
2
votes
5answers
658 views

How do a firewall's rules for individual programs work?

I kind of know that how a firewall's rules for IP/port work, but I have no idea how a firewall deals with individual programs. In other words, how does the firewall know a program wants to access the ...
2
votes
6answers
2k views

How do I prevent data from leaving my network?

I have a network of about 10 computers and I want to prevent sensitive data and source code leaks. To achieve that, I would like to block all file uploading / attaching. What are the options ...
2
votes
3answers
9k views

What, specifically, does the Windows Firewall do?

My understanding of the situation is that, when the Windows firewall is off, every port on the computer (all 65535 of them) is fully open. This means that any application running on the computer can ...
2
votes
3answers
2k views

How to block the websites on client machines

In our office we are blocking sites like Facebook, Twitter etc.The problem is that some of the users bypass our proxy and firewalls through external proxy sites like www.youhide.com or ...
2
votes
4answers
2k views

Best way to push data to a client without being blocked by firewall

I'm asking this question here since I think people on this forum probably have the best knowledge of firewalls and routers. Say I'm designing a multi-player game and I want to push data to the client ...
2
votes
2answers
7k views

How secure is blocking all incoming connections on my ADSL or cable router?

My router, an up-to-date ADSL Fritz!Box 7340 router with a fixed leased IP address, has been configured to block all incoming traffic. Assuming, for the sake of argument, no extra security is ...
2
votes
2answers
739 views

Identify if files are being transferred from my computer over the internet

This may seem like a silly question to most, but... I recently has some spyware infected on my machine, which I have since gotten rid of. Using a couple of scanners (that come recommended on various ...
2
votes
2answers
1k views

Firewall & TCP Traffic

I have a question regarding network firewalls and TCP traffic. When a firewall rule is set to block either inbound traffic, outbound traffic, or both on a port, does that only apply to initial ...
2
votes
2answers
209 views

Access via http to other protocols and ports!

Our firewall only allows HTTP port 80 but we have detected that a user accesses some other protocols and ports that we deny in our firewall. We know that he has developed an application (Console ...
2
votes
2answers
348 views

Web Application Firewall Rules

For Network Layer Firewalls we have different sort of redundancy and consistency checks like rule shadowing, that can impact the performance of firewall. Do similar kind of checks can be applied on ...
2
votes
3answers
6k views

windows firewall turns OFF automatically

It seems pretty weird but for some reason, the Windows 7 firewall turns off. After I turn the firewall on in the control panel, it seems that it turns itself off when I go back to the control after I ...
2
votes
2answers
4k views

IPTables default security rules for a gateway/router?

On a router such as dd-wrt or tomato, what would be some default iptables rules? I am asking for rules on a router/gateway - For example; blocking SYN flood attacks, or XMAS attacks. The basic ...
2
votes
3answers
1k views

How to prevent attacks to server

I have 3 CentOS server configured for my applications. Recently I recognized that there is so many attacks to my servers. I have so many logs about attempt to login to my servers using sshd from ...
2
votes
2answers
249 views

Expose the source code repository externally or allow VPN access?

To allow third party consultants, offshore developers and contractors working on the code, we can expose our Git repository externally. Or we can grant VPN access to the external parties and limit ...
2
votes
3answers
941 views

iptables: plaintext password protection

I'd like to find a way to block or restrict my access to the web-pages where my password is sent as a plaintext on the internet. Let's assume if I have the same password for all web-pages, is it ...
2
votes
2answers
419 views

Telnet port open on my router public IPv6 address

Recently I upgraded my home router into this one. It is a cheap one, but it has features I needed: IPv6 support and Gigabit Ethernet. So I decided to give IPv6 a try. I configured a Hurricane ...
2
votes
2answers
529 views

What is the real benefit of a three tier architecture?

As per title, what is the real advantage of using three tiered architecture, where the user interface in one layer, the second layer for application and third layer for database? I can understand that ...